The manufacturing of golf clubs and balls requires extensive testing to determine which equipment will prove most advantageous for golf players. Many tests are performed during the designing of equipment in order to determine which materials are best suited for a particular piece of equipment, such as a club or ball. Testing the properties of a particular type of material enables designers to determine the best mode of applying these materials as well as potential product performance advantages.
To determine the properties of different materials, manufacturers have employed many different testing machines. Due to the high rate of deformation associated with golf ball use, these testing machines involve forming a sample of a material and firing it towards a flat surface, such as an immovable plate. These machines often fire the sample out of a firing mechanism, towards the immovable plate. The sample then strikes the immovable plate and rebounds off of it. A sensing system is typically placed in between the firing mechanism and the immovable plate to record the flight of the sample. Based on the output of the sensing system, the properties of the collision, such COR, and contact duration are measured and material characteristics such as elastic modulus and resiliency may be determined.
Existing testing machines, such as the one described above, have many drawbacks. For example, in order to cause the sample to rebound off the immovable plate in a predictable manner, it is often necessary to manufacture a substantially spherical sample. Manufacturing a spherical sample of a material may require specialized molds, unique degassing equipment, or large material quantities, and thus complicates and increases the cost of material tests. These methods are also more time consuming because they require the uniquely molded material sample to be formed according to strict specifications. Furthermore, these testing machines require a new spherical sample to be manufactured if an existing one is deformed in any way, such as by chipping, cracking, tearing, or change in sphericity.
Thus, a continuing need exists for a testing machine that is capable of repeatedly and reliably testing the physical properties of a material without being susceptible to the strict specifications required for material samples used in prior testing machines. A need also exists for an apparatus which does not require a large volume of sample material for test specimen production.